1. Field of the Invention
The present invention relates to a front body structure of a vehicle which is provided with a dash panel extending in a vertical direction and forming a front end wall of a crew""s cabin, a floor panel continuously extending rearward from the dash panel, and a tunnel portion protruding upward, in a substantially center portion of the floor panel, and extending in a longitudinal direction of the vehicle.
2. Description of the Prior Art
In conventional, as disclosed in U.S. Pat. No. 4,930,836 corresponding to Japanese Patent Laid-Open Publication No. Hei 2-20423, there has been disclosed a body structure of a vehicle in which a door-opening is provided in a side body, and the door-opening is opened and closed by a front door and a rear door which constitute a free-style type door.
In the prior art, a door opening with a center pillar less structure is formed in a side body of the vehicle. And, a front door is supported to open and close via front door hinges on a front line portion of the door-opening, while a rear door is supported to open and close via rear door hinges on a rear line portion of the door-opening.
When applying the above-mentioned free-style type of door with the center pillar less structure to an automobile and setting a door-opening size thereof to be larger in order to secure the convenience in getting on and off the vehicle, it is desired to develop a vehicle body with sufficient high body rigidity. Because, in this case, the door-opening is considerably large, and in addition to this fact, a hinge pillar should bear a load when an enlarged door is opened and closed.
Further, in conventional, as a vehicle body structure of a vehicle, as disclosed in Japanese Patent Laid-Open Publication No. 2000-238667, there has been disclosed a body structure of a vehicle which is provided with a floor tunnel portion protruding upward and having a bottom-open reverse U-shaped cross sectional structure, and a supplementary frame (tunnel member) provided in an upper part of the floor tunnel portion and having a closed cross sectional structure.
When applying such a vehicle body structure to a vehicle body having free-style type doors with a center pillar less structure, it is possible to improve a floor rigidity and a body rigidity of the vehicle. However, in this case, it is difficult to restrain a backward movement of a dash panel at a time of a head-on collision of the vehicle, also it is difficult to restrain a intrusion amount of a side-sill or doors into a crew""s cabin at a time of a side collision of the vehicle.
Furthermore, in this case, so as to transmit a collision load to the floor tunnel portion at a time of a head-on collision of the vehicle, a front extension portion for connecting the supplementary frame (tunnel member) to the front side-frame is required, so that there are problems that a number of parts and a number of assembling steps are increased, and the structure thereof becomes more complex.
An object of the present invention is to provide a front body structure of a vehicle which is capable of enhancing the body durability and restraining a backward movement of a dash panel at a time of a head-on collision of the vehicle, further capable of restraining a intrusion amount of a side-sill or doors into a crew""s cabin at a time of a side collision of the vehicle.
Another object of the present invention is to provide a front body structure of a vehicle which is capable transmitting a collision load at a time of a head-on collision to the tunnel portion in spite of a simple structure, thereby improving durability at a time of collision.
In accordance with a first aspect of the present invention, there is provided a front body structure of a vehicle including: a dash panel extending in a vertical direction and constituting a front end wall of a crew""s cabin; a floor panel continuously extending rearward from said dash panel; and a tunnel portion protruding upward and extending in a longitudinal direction of the vehicle, said tunnel portion being provided in a substantially center portion of the floor panel, wherein said dash panel is provided with a dash cross member structured such that one end portion is jointed to a side surface of said tunnel portion, a middle portion extends in the vehicle widthwise direction along the clash lower panel, and another end portion is connected to a hinge pillar inner.
The above-mentioned dash panel may consist of a dash lower panel.
According to the structure mentioned above, since the dash cross member is arranged among the dash panel, the tunnel portion and the hinge pillar, it is possible to enhance the body durability by dispersing an input load of the dash panel into the tunnel portion and the hinge pillar via the dash cross member, at a time of a head-on collision of the vehicle. As a result, it is possible to restrain a backward movement of the dash panel.
Also, at a time of a side collision of the vehicle, it is possible to restrain a intrusion amount of a side-sill or doors into the crew""s cabin by dispersing a side collision load into the tunnel portion via the dash cross member.
In one embodiment of the present invention, the above-mentioned dash cross member is provided so as to extend substantially in a horizontal vehicle widthwise direction at a predetermined height position upward apart from a height of a horizontal part of the floor panel.
In this case, since the height position of the dash cross member is set to the above-mentioned predetermined height position, it is possible to enhance the rigidity (or strength) of the hinge pillar by means of the dash cross member. Especially, it is possible to enhance the durability against a side collision.
In one embodiment of the present invention, a tunnel member extending in the longitudinal direction of the vehicle along the tunnel portion to form a closed cross section is provided on a surface of the tunnel portion.
In this case, it is possible to enhance the rigidity of the floor and the vehicle body by arranging the tunnel member.
In one embodiment of the present invention, the dash cross members are arranged so as to constitute a pair of right and left pieces, and each of the right and left dash cross members is jointed to the tunnel member provided on the surface of the tunnel portion.
In this case, at a time of a side collision in either right side or left side, it is possible to disperse a collision load to the tunnel member via the hinge pillar and the dash cross member, and to receive the collision load by the high rigid tunnel member. As a result, it is possible to restrain more effectively the intrusion amount of the side-sill or the doors into the crew""s cabin.
In one embodiment of the present invention, the tunnel member is arranged all along the length of the tunnel portion in the longitudinal direction of the vehicle, and a front end portion of said tunnel member is connected to the dash panel.
In this case, it goes without saying that it is possible to further enhance the floor rigidity and the vehicle body rigidity by the tunnel member extending all along the length of the tunnel portion. Since the front end portion of the tunnel member is connected to the dash panel, it is possible to remarkably enhance the body durability by dispersing an input load of the dash panel into the tunnel portion and the hinge pillar via the dash cross member, at a time of a head-on collision of the vehicle.
In one embodiment of the present invention, a rear end of a front side-frame is connected to such a portion that corresponds to a connected portion by the dash cross member in the outer side surface of said dash panel.
In this case, at a time of a head-on collision, it is possible to disperse a transmitted load from the front side-frame to the tunnel portion and the hinge pillar via the dash panel and the dash cross member. Thereby, it is possible to enhance the durability and the rigidity of the vehicle body.
In one embodiment of the present invention, a door-opening is formed in a side portion of said vehicle, and said door-opening is provided with an annular reinforcement which integrally and continuously extends in an annular manner along said door-opening.
In this case, by arranging the annular reinforcement, it is possible to enhance the body rigidity and the torsional rigidity of the vehicle body, and to enhance the operating stability of the vehicle.
In one embodiment of the present invention, the end portion in the hinge pillar side of the dash cross member is jointed to the annular reinforcement via the hinge pillar inner.
In this case, by jointing the end portion in the hinge pillar side of the dash cross member to the high rigid annular reinforcement, it is possible to remarkably enhance the body rigidity and to enhance the durability against a head-on collision load and a side collision load.
In one embodiment of the present invention, the door-opening is opened and closed by a free-style type door consists of a front door supported by a hinge at a front portion thereof and a rear door supported by a hinge at a rear portion thereof.
In this case, the above-mentioned effects are shown more satisfactorily with respect to a vehicle having free-style type doors. Especially, since the hinge pillar supporting the front portion of the front door via a hinge is reinforced by the dash cross member, it is possible to secure a sufficient supporting rigidity of the front door even if the door-opening and the front door is set to be large.
In accordance with a second aspect of the present invention based on the first aspect of the same, there is provided a front body structure of a vehicle, wherein a front frame extending in the longitudinal direction of the vehicle is arranged in a front side of the dash panel, and a rear end portion of the front frame extends in a vehicle widthwise direction to extend rearward along an outer side surface of the tunnel portion, and forms a closed cross sectional portion with respect to the tunnel portion to be jointed to the tunnel portion.
The dash panel having the structure mentioned above may correspond to a dash lower panel, and the front frame having the structure mentioned above may correspond to a front side-frame.
It is to be noted that the xe2x80x9cback surfacexe2x80x9d of the tunnel portion means a reverse surface of a plate-like member forming the tunnel member, and the back surface faces to outer side of the crew""s cabin. On the other hand, the xe2x80x9csurfacexe2x80x9d or xe2x80x9cupper surfacexe2x80x9d of the tunnel portion means a surface of a plate-like member forming the tunnel member, and the surface (or upper surface) faces to inner side of the crew""s cabin.
According to the structure mentioned above, the rear end portion of the front frame extending in the vehicle widthwise direction is jointed to the back surface of the tunnel portion. And the closed cross section is formed between the rear end portion of the front frame and the tunnel portion. Therefore, it is possible to transmit a load at a time of a head-on collision from the front frame to the tunnel portion in spite of a simple structure, thereby, it is possible to improve durability at a time of a collision.
In one embodiment of the present invention, a tunnel member extending in the longitudinal direction of the vehicle along the tunnel portion to form a closed cross sectional portion is provided in an internal surface of the tunnel portion.
The tunnel member having the structure mentioned above may correspond to a high mount backbone frame.
In this case, it is possible to transmit the collision load at a time of the head-on collision to the tunnel portion and the tunnel member by arranging the tunnel member. Whereby, it is possible to further improve the durability at a time of the collision. And, simultaneously, it is possible to improve floor rigidity and vehicle body rigidity by arranging the tunnel member, and it is further possible to enhance a torsional rigidity of the front body of the vehicle.
In one embodiment of the present invention, the front frame rear end portion jointed to the outer side surface of the tunnel portion, and the tunnel member jointed to the internal surface of the tunnel portion are arranged to overlap in the longitudinal direction of the vehicle.
In this case, the durability of the vehicle body at a time of the collision is further improved by the overlapping structure as mentioned above.
In one embodiment of the present invention, the rear end portion of the front frame extends in the vehicle widthwise direction along the outer side surface of the dash panel to be jointed at least to a torque box.
In this case, since the load at a time of the collision is transmitted to a side-sill via the torque box and the load is also transmitted to the tunnel portion and the tunnel member, thereby making it possible to disperse the collision load, it is possible to restrict the deformation of the vehicle body.
In one embodiment of the present invention, the rear end portion of the front frame extends in the vehicle widthwise direction along the outer side surface of the dash panel, and the widthwise side portion thereof is jointed to a side-sill portion extending in the longitudinal direction of the vehicle.
In this case, since the load at a time of the collision is transmitted to the side-sill, the tunnel portion and the tunnel member, thereby making it possible to disperse the collision load, it is possible to restrict the deformation of the vehicle body.
In one embodiment of the present invention, the rear end portion of the front frame is connected to the floor frame which is jointed to a back surface of the floor panel to form a closed cross sectional portion and extends in the longitudinal direction of the vehicle.
In this case, the front frame is connected to the floor frame extending in the longitudinal direction of the vehicle. Therefore, it is possible to transmit and disperse the collision load not only to the tunnel portion but also to the floor frame forming the closed cross section with respect to the floor panel. As a result, it is possible to restrain more effectively the deformation of the vehicle body.
In one embodiment of the present invention, the tunnel portion is formed in a hat-like shaped cross section. The front frame is constituted by a pair of right and left frames, and rear end portions of a pair of right and left front frames form a pair of closed cross sectional portions in both corners in an upper portion of the tunnel portion.
In this case, a pair of right and left closed cross sectional portions are formed by the rear end portions of a pair of right and left front frames, and both corners in the upper part of the back surface in the tunnel portion formed in the hat-like shaped cross section (a portal cross section). Therefore, it is possible to enhance a vehicle body strength, and it is possible to intend to improve durability at a time of the collision, by the closed cross sectional structure.
In one embodiment of the present invention, the tunnel member is arranged all along the length of the tunnel portion, and a front end portion of the tunnel member is connected to the dash panel.
In this case, it goes without saying that it is possible to further enhance the floor rigidity and the vehicle body rigidity by the tunnel member extending all along the length of the tunnel portion. Since the front end portion of the tunnel member is connected to the dash panel, it is possible to restrict a backward movement of the dash panel at a time of the head-on collision of the vehicle.